The present invention applies to fence and barrier systems; more particularly, the present invention applies to gate or door opening systems typically used with fences or barriers.
For as long as fences or barriers have been used to enclose spaces, there has been a need to include in the fence or barrier system a portal for gaining access to the enclosed space. For security and for many other reasons, the portal to which access to the enclosed space may be gained typically includes a movable closure. Such movable portal closures may be opened in a variety of different directions to include both horizontal (parallel to the earth""s surface) and vertical (perpendicular to the earth""s surface). The present invention pertains to portal closures whose movement is substantially horizontal, such horizontal movement being along either a linear or an arcuate path with respect to the fence or barrier system.
Numerous systems have been used over the years to open portal closures such as gates or doors. One of the most common systems is a chain-drive system wherein the teeth on a rotating, stationary mounted, sprocket are used to engage the openings in a chain, which chain is mounted to the portal closure. Such chain drive systems are slow, cumbersome, and prone to breakage. Such chain drive systems are also subject to the effects of weather; particularly the destructive effects of repeated exposure to moisture. Gates which open on an arcuate path typically use long arms--which long arms are prone to breakage.
There is therefore a need in the art to provide a system for opening a portal closure which will be fast operating, easy to use, and low in maintenance.
A fast operating, easy to use, and relatively maintenance free system and method for moving a horizontally movable gate or door includes a stationary mounted linear induction motor, a magnetic stepper motor or a linear reluctance motor. A reaction piece, either a reaction plate or a reaction rod, is caused to move by the linear induction motor, the magnetic stepper motor or the linear reluctance motor. The movement of the reaction piece, which is mounted to the gate or door, is then used to control the opening and closing of the gate or door. When it is desired to open the gate or door, the linear induction motor the magnetic stepper motor, or the linear reluctance motor is activated. The activation of the motor causes the reaction plate or reaction rod to move with respect to the position of the motor. Because the reaction plate or reaction rod is mounted to the gate or door, the movement of the reaction plate or reaction rod causes the gate or door to move to an open position so that access to an enclosed space is permitted. Alternatively, the movement of the gate or door may be to a closed position so that the opening to the enclosed space is blocked.